The present invention relates to a method and a device for treating opacities and/or hardenings of an unopened eye. Specifically, the present invention relates to a laser system and a method for cleaning, in particular, the ageing human eye from gray hazes in the cornea, the lens or the vitreous body to restore transparency in the eye.
In ophthalmology, it is known that, in particular in the ageing eye, opacities develop in the lens (cataract) or in the vitreous body or the cornea. At the advanced stage, the treatment is presently limited to replacing the lens with a plastic lens during a cataract surgery, replacing the vitreous body with silicone oil by vitrectomy, or also to transplanting the cornea. It is known to carry out the surgery of the cataract and the vitrectomy of the vitreous body using a laser. During a surgery, the laser beam is in both cases led directly to the tissue to be treated. A proven efficient laser is, in particular, the Er:YAG laser having the emission wavelength of 2.94 μm whose radiation is strongly absorbed by water. For conveying the laser radiation, cannulas with optical waveguides are led up to the location of treatment. Although cannulas having diameters of approximately 1 mm are manufacturable now, the necessity of the surgical intervention remains. A device for carrying out a laser phacoemulsification is described, for example, in German Patent 19718139.
Also known are surgical techniques in the case of which the eye is not opened but the laser light is guided into the eye via the normal path of the visual process. These techniques include the possibility of attaining an optical disruption inside of the cornea by focusing fs laser pulses (300 fs, 1 μl, 780 nm), resulting in the formation of blisters. By folding open a lamella, it is possible to prepare an intrastromal lenticle whose removal brings about a refractive correction. It is known, moreover, that the gray after-cataract membrane can be disruptively removed with the aid of ns pulses of a Q-switched Nd:YAG laser.
In known methods heretofore, apart from medicamentous methods, it was not possible to treat the clouded regions already at the initial stage. Thus, the known laser techniques are not suitable for removing the clouded regions in the eye without opening the eye. Therefore, it is an object of the present invention to provide a method and a device which make it possible to dissolve clouded regions in the eye.
A further phenomenon which occurs in old age is presbyopia. One reason for this lies in the hardening of the lens, which can occur, for example, due to deposit of substances. Apart from the utilization of spectacles, photorefractive keratectomy (PRK) has often been used recently for correcting the visual defect. Removal of the hardening itself has not been possible in known methods heretofore. Therefore, it is a further object of the present invention to provide a device with which the lens' ability to contract is increased again.